1. Field of the Invention
The present invention relates generally to cooling a central processing unit (CPU) of a computer.
2. Background of the Invention
Because of its critical role, the CPU of a computer generates a significant amount of heat but must operate at a sufficiently low temperature to avoid degradation in its performance. In the typical personal computer, the CPU is cooled by placing a finned heat sink directly above and in thermal contact with the CPU. A fan is positioned above the heat sink. The fan generates a flow of air immediately above the heat sink, removing the heat generated by the CPU away from an area near the CPU and heat sink, in turn, cooling the surrounding air. Because heat transfer from an object to its environment increases as the temperature of the air surrounding it decreases, this fan helps to keep the CPU cool.
However, since the CPU is typically contained within a computer housing, the heat generated by the CPU and dispersed by the fan does not necessarily escape the computer's housing. Therefore, a second fan is commonly used to blow this heat, as well as the heat generated by the other components inside the computer's housing, outside the housing to the environment. But fans tend to be one of the noisiest, if not the noisiest, components inside a computer. Therefore, the use of this additional fan increases the noise inside the computer. The extra noise is unpleasant for the user, especially when the computer is used for multimedia applications. Also, this additional fan takes up space inside the computer main unit. In small profile computer systems, space is at a premium, so the additional fan is undesirable. Lastly, the fan directly over the CPU may cause vibrations in the CPU, which may affect its performance.